In any Internet application download/upload of large data files has always been a major problem. There are several weird problems related to transfer of data through Internet protocols (IP) such as HTTP or FTP. Most of these problems are related to frequent error conditions that may occur during any long download/upload process. Errors like a broken transmission, lost connection, stalled transfer and so on are very common problems for large data file transfers.
An example of a typical internet service where these problems become even worst is Print On Demand Services since very large data files (i.e. more than 10 Mb) are exchanged over the Internet.
A Print On Demand (POD) Service generally allows a customer to buy printed reproductions of certain data files, which can be available on particular web sites or on the customer's own computer. Such data files, once selected by the customer, are transferred, preferably via Internet, to a print service facility/provider for their reproduction, and often via a modem. For example Mediaflex.com (http://www.mediafiex.com) offers an Internet accessible printing service using a standard web site.
Conventional print service providers (PSPs) comprise one or a plurality of printers in a singles physical location, e.g. a print shop or a print room, which provide to a customer a printing service for posters, brochures, leaflets, copies of photographs and the like. Typically a print service provider may comprise one or more large format printers capable of printing to large format size media, i.e. a HP DesignJet printer.
Printing speed is an important feature for printers of all types, in particular for printers at print service facilities. In a POD environment if a customer desires to buy a bitmap image that fills an 8½×11 inches page at 300 dots-per-inch (dpi) in 24 bit colour, this uncompressed image file would be over 22 Mb in size. Even compressing the file using JPEG compression would still leave a file several MB in size. Then, such file is download from the server where it is stored to the print service provider for its printing. With a modem operating at 56.6 Kb/s, this download would take several minutes, If working at full speed and not experiencing any of the above error cited conditions. During this time the printer sits idle as it waits to receive data and it will not start receiving data, i.e. printing. Clearly if the downloading process, for any of the above reasons, fails, the time the printers stay idle get bigger and bigger causing frustration and damages (printers not printing the required job) to the PSP's owner.
However not only the downloading time has accrued problems, but also the rest of the traditional sequential printing process, which causes the growth of the total print time for each print to further unacceptable levels in particular for a PSP, which is trying to maximise the amount of time during which each printer is actually printing.
With reference to FIG. 1, traditionally printing of a raster data has been based on a sequence of the following tasks: “download”, “load”, “process”, print”, “I/O”. For instance a 4 Mb JPEG (or TIFF, PhotoCD or the like) compressed raster file has been traditionally printed by:                downloading: take 4 Mb of compressed raster data from the internet;        loading: decompress 4 Mb data into 50 Mb memory data;        processing: apply image processing to 50 Mb memory data;        printing: send 50 Mb memory data through the print driver, eventually till the print spooler; and        I/O: send 4 Mb-100 Mb (compressed/uncompressed) data through the I/O, till the printer, which eventually starts printing.        
According to FIG. 1, a PSP, by printing several images, has to repeat for each of these such sequence of tasks, which means that long period s of “printing process” time are always required. Then, there is a need, in particular for a PSP, for methods and systems which can increase the number of prints that can be produced by each printer, optimising such printing process.
Applicant realises that most of the above stated problems, occurring while downloading/uploading files from/to a server to/from a client computing device, are not likely to appear when small files (generally less than 1 Mb) are transferred.